Hi driskal,

Both Alienware models are one of the top most computers in gaming. If you buy any one of them you would not repent.

Alienware auroras come with 2nd generation processor, memory can go up to 32GB, uses NVIDIA GeForce GTX 690 video cards and needs to use a 875 Watt Multi-GPU Approved Power Supply.

You may also use the below to get more info on Alienware aurora:

http://dell.to/vZVsl2

Alienware X51 comes with 3rd generation processor, maximum memory of 8GB, uses NVIDIA GeForce GTX 660 video cards, can use 240 Watt Power Supplies.

You may also use the below to get more info on Alienware X51:

http://dell.to/HURkQa

If you have further questions do reply to the same post.

Both rigs are awesome, but the Aurora can handle a stronger video card. The result is better graphics and higher FPS (specially since you bought for gaming).

As Porras said, the system is easily upgradable and even if you purchased it with a single video card (assuming you did) it will be simple to add dual graphics and boost the performance. I'd say you made a good decision.

Indecision is one of the central issues solved with counseling and psychology.

Counseling and Psychological Services provide professional help for Conflicts and indecisiveness.

Great input from my partner :) I just wanted to add that if you are planning to do upgrades in the future it was better to get the Aurora :) It has more space and compatibility for them.

Stay with the R4. I have an R3 and works great, plus like mentioned above you will want to upgrade in the future. Very limited on the X51. Just bought my son an R4 and he loves it. Heck, his is faster than mine :(

Buy anything other than Dell I have an Aurora R3 purchased in January 2012 can't run windows 8 and never will be able to due to very poor support your computer will only be able to run what it is shipped with